Never top off your tank

hello and welcome to the car care now channel today we'll be talking about a very controversial subject why you should never top off your gas tank or you should never overfill your car with gas once it clicks stop be on your way let's dig into this deeper after this as a professional mechanic this is one of the most asked questions people ask why it's not just that should i or should i not it's why people often argue i've been doing this forever nothing has happened in my car well i'm here to tell you you've been lucky so let's move on to this interactive slide that i made so i can explain how everything works this is the basic diagram for the system i know this looks like a lot but bear with me you have your fuel tank your fuel tank has a hose that is connected to a device called the vapor canister the vapor canister has this little magic charcoals inside of it they trap gas fumes the idea of this whole system is gas fumes you don't want those gas fumes going out to the environment harming the environment or you don't want them going into your garage into your house everybody knows how horrible gas fumes are this whole system is designed so you would trap these gas vapors inside the vapor canister and then when the engine runs there's another hose that goes from the vapor canister to the engine there's a little valve called the first valve when that when the computer opens that valve the engine takes these vapors burns them in the engine and you never get them in your garage in your house so there's also the vent valve the vent valve is always closed there's times with the red valve open to draw in fresh air inside never out if the vent valve malfunctions you're going to have vapor smell all over your house all over your car so that's the basic outlet outline of this system moving on when you fill your car with gas you're gonna put the gas here as the gas starts filling up in your tank the gas will be red the vapor the fumes the gas fumes will start heading in the pipe we're going to make the gas fumes yellow so as you continue to fill your tank the vapor canister will fill with fumes now your fueled you're done nothing came out the pump clicked and you're done now when the your engine is running the little purge valve opens up the computer commands it to open it's open now the vapors go to the engine they get burned by the engine and they're gone as the vapor cancer level comes down the fresh air comes in fresh air fills everything fills all the line and everything is happy and beautiful your gas tank goes down this cycle repeats over and over as you drive your car no gas fumes comes out of the system it's all sealed now once your gas tank comes down you're coming to mt and here we go to the gas station trying to overfill our car same thing the beautiful cycle is happening the vapors are going to the vapor canister but when you start overfilling your tank here's what happens you start forcing fuel to the vapor canister you see how the red arrows are now going to the vapor canister once you fill the vapor canister with raw gasoline or liquid gasoline the vapor canister is damaged it's done there's charcoals or little rocks inside of there once they get wet they're done they no longer can contain the fumes and after this if you continue to do this now you're going to ruin the vent valve and this is where the first huge problem will happen once you ruin the vent valve because all this charcoal now got stuck on the valve and now no longer can close this is the first complaint my car smells like gas my garage smells like gas and worst case scenario my house smells like gas this is terrible then next worst case scenario gas starts going to the purge valve damages the purge valve now your check engine light comes on now you have all kinds of problems is it worth it is it really worth it for the extra two miles that you're gonna drive for the extra i don't know quarter of a gallon that you put in your gas tank or you know i am ocd i'll admit everyone likes to round to a even number at the gas station it's not worth it so let's stock some money let's talk how much does some of this stuff cost vapor canister prices for parts these are very general averages 300 to 1200 dollars just for the parts labor 200 to 500 dollars now let's talk about the vent valve parts guess what most cases the vent valve is part of the vapor canister so now we're talking about the same thing purge valve parts 75 200 labor another 75 200 how much is the total it's not worth it please this is not worth it the system that are affected by this is called the evaporative emission system or evap for short most people call it evap and it is the single most misdiagnosed system by the professional mechanic community it's just a very difficult system to diagnose sometimes especially when you add a little bit of overfilling your tank to it in 1996 the government mandated the system so if your car is 96 and at newer this applies to you if you drive 55 chevy this is not for you so now you know exactly why you should not overfill your car or top off your car once it clicks put the nozzle back be on your way that is the best way to avoid you spending thousands and dollars fixing something that is totally unnecessary i see this all the time and i see people's faces when you tell them the quote for repair how their faces light up when they know that they caused this please don't be that person that's at my dealership with their face lit up because of the repair bill for something that is totally unnecessary i hope this video was helpful or informative for you if you liked it please subscribe to the channel like the video leave a comment down below may the lord bless you and you have a wonderful day

Channel: The Car Care Nut

Views: 167,516

Rating: 4.9307189 out of 5

Keywords: never top off your tank, gas tank, top off, top of, car advice, car advise, auto repair, evap problems, evap problem, car gas, car tank, fuel smell, check engine light, p0441, p0446, p0442, diyrepair, purge valve, purge, charcoal, charcoal canister, canister, vapor, vapor canister, filling up your gas tank, fuel efficiency, overfill gas tank, topping off gas tank, things not to do, car repair, dumb things, gas station tips, filling gas tank, rav4 prime, overfill car

Id: jPiiqcDxDxY

Length: 7min 24sec (444 seconds)

Published: Tue Jul 07 2020